Proton conducting electrolyte membrane having reduced methanol permeability and the use thereof in fuel cells

摘要

The present invention relates to a proton-conducting electrolyte membrane obtainable by a process comprising the steps: A) swelling a polymer film with a liquid comprising a vinyl-containing sulphonic acid and B) polymerising the vinyl-containing sulphonic acid present in liquid introduced in step A). A membrane according to the invention is very versatile on account of its excellent chemical and thermal properties and may be used, in particular, as a polymer electrolyte membrane (PEM) in what are known as PEM fuel cells.